IHME projection: COVID-19 ‘Deadly December’ can be mitigated with vigilance around masks, social distancing

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SEATTLE, WA – In the first global projections of the COVID-19 pandemic by nation, the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s School of Medicine is predicting nearly 770,000 lives worldwide could be saved between now and January 1 through proven measures such as mask-wearing and social distancing.

Cumulative deaths worldwide expected by January 1 total 2.8 million, about 1.9 million more from now until the end of the year. Daily deaths in December could reach as high as 30,000.

“These first-ever worldwide projections by country offer a daunting forecast as well as a roadmap toward relief from COVID-19 that government leaders, as well as individuals, can follow,” said IHME Director Dr. Christopher Murray. “We are facing the prospect of a deadly December, especially in Europe, Central Asia, and the United States. But the science is clear and the evidence irrefutable: mask-wearing, social distancing, and limits to social gatherings are vital to helping prevent transmission of the virus.”

The Institute modeled three scenarios:

  • A “worst case” in which mask usage stays at current rates and governments continue relaxing social distancing requirements, leading to 4.0 million total deaths by the end of the year;
  • A “best case” of 2.0 million total deaths if mask usage is near-universal and governments impose social distancing requirements when their daily death rate exceeds 8 per million; and
  • A “most likely” scenario that assumes individual mask use and other mitigation measures remain unchanged, resulting in approximately 2.8 million total deaths.

The references to 750,000 lives saved and 30,000 daily deaths in December represent the differences between the “best case” and “most likely” scenarios.

U.S. Forecast

The U.S. forecast totals 295,011 deaths by December. As of today when, thus far, 158,000 have died, IHME is projecting approximately more than 137,000 deaths. However, starting today if 95 percent of the people in the U.S. were to wear masks when leaving their homes, that total number would decrease to 228,271 deaths, a drop of 49 percent. And more than 66,000 lives would be saved.

Masks and other protective measures against transmission of the virus are essential to staying COVID-free, but people’s inconsistent use of those measures is a serious problem, said IHME Director Dr. Christopher Murray.

“We’re seeing a rollercoaster in the United States,” Murray said. “It appears that people are wearing masks and socially distancing more frequently as infections increase, then after a while as infections drop, people let their guard down and stop taking these measures to protect themselves and others – which, of course, leads to more infections. And the potentially deadly cycle starts over again.”

Murray noted that there appear to be fewer transmissions of the virus in ArizonaCaliforniaFlorida, and Texas, but deaths are rising and will continue to rise for the next week or two. The drop in infections appears to be driven by the combination of local mandates for mask use, bar and restaurant closures, and more responsible behavior by the public.

“The public’s behavior had a direct correlation to the transmission of the virus and, in turn, the numbers of deaths,” Murray said. “Such efforts to act more cautiously and responsibly will be an important aspect of COVID-19 forecasting and the up-and-down patterns in individual states throughout the coming months and into next year.”

Murray said that based on cases, hospitalizations, and deaths, several states are seeing increases in the transmission of COVID-19, including ColoradoIdahoKansasKentuckyMississippiMissouriOhioOklahomaOregon and Virginia.

“These states may experience increasing cases for several weeks and then may see a response toward more responsible behavior,” Murray said.

In addition, since July 15, several states have added mask mandates. IHME’s statistical analysis suggests that mandates with no penalties increase mask-wearing by 8 percentage points. But mandates with penalties increase mask-wearing by 15 percentage points.

“These efforts, along with media coverage and public information efforts by state and local health agencies and others, have led to an increase in the U.S. rate of mask-wearing by about 5 percentage points since mid-July,” Murray said.

Mask-wearing increases have been larger in states with larger epidemics, he said.

IHME’s model assumes that states will reimpose a series of mandates, including non-essential business closures and stay-at-home orders, when the daily death rate reaches 8 per million. This threshold is based on data regarding when states and/or communities imposed mandates in March and April, and implies that many states will have to reimpose mandates.

As a result, the model suggests which states will need to reimpose mandates and when:

  • August – ArizonaFloridaMississippi, and South Carolina
  • September – Georgia and Texas
  • October – ColoradoKansasLouisianaMissouriNevadaNorth CarolinaOregon, and Washington.
  • November – AlabamaArkansasCaliforniaIowaNew MexicoOklahomaUtah, and Wisconsin.

However, if mask use is increased to 95 percent, the re-imposition of stricter mandates could be delayed 6 to 8 weeks on average.

The model also assumes that 50 percent of school districts in each state will opt for online instruction only for the 2020–2021 school year.

“As data emerges on actual school patterns, we will incorporate them into our future revisions of forecasts,” Murray said. “We recognize that, given mask-wearing, the likely restrictions on after-school activities, and the potential for some parents to avoid engaging in school-related functions, our estimated impact of school openings may be overly pessimistic.”

NH Outlook

Based on IHME projections for New Hampshire, maintaining mask-wearing and social distancing protocols will keep statewide infection and death rates comparatively low.

Global Outlook

“This first global forecast represents an opportunity to underscore the problem with herd immunity, which, essentially, ignores science and ethics, and allows millions of avoidable deaths,” Murray said. “It is, quite simply, reprehensible.”

Top 10 nations with the highest cumulative deaths on January 1:

Worst-case scenarioMost likely scenarioBest-case scenario
India: 916,688 (range of 562,203–1,431,708)India: 659,537 (range of 415,118–1,087,533)India: 484,981 (range of 316,111–819,426)
United States of America: 620,029 (range of 463,361–874,649)United States of America: 410,451 (range of 347,551–515,272)United States of America: 288,381 (range of 257,286–327,775)
Japan: 287,635 (range of 25,669–758,716)Brazil: 174,297 (range of 163,982–185,913)Brazil: 160,567 (range of 152,483–169,483)
Spain: 180,904 (range of 97,665–282,075)Mexico: 138,828 (range of 125,763–156,493)Mexico: 130,545 (range of 118,201–147,963)
Brazil: 177,299 (range of 166,656–189,259)Japan: 120,514 (range of 10,301–492,791)Japan: 104,808 (range of 7,971–456,224)
Mexico: 157,264 (range of 139,863–183,739)Russian Federation: 94,905 (range of 57,575–170,048)Spain: 66,508 (range of 41,980–117,239)
Philippines: 117,721 (range of 27,525–176,324)France: 73,743 (range of 44,693–161,349)United Kingdom: 59,819 (range of 57,572–65,411)
France: 116,415 (range of 51,021–342,047)United Kingdom: 69,548 (range of 59,680–96,669)Philippines: 58,030 (range of 7,552–137,358)
Russian Federation: 112,367 (range of 63,165–214,363)Spain: 69,445 (range of 43,306–122,913)France: 46,623 (range of 38,070–69,559)
Netherlands: 94,332 (range of 21,815–186,842)Philippines: 58,412 (range of 7,660–136,079)Peru: 46,528 (range of 44,161–48,557)

Top 10 nations with the highest cumulative death rate per 100,000 on January 1:

Worst-case scenarioMost likely scenarioBest-case scenario
Netherlands: 549.8 (range of 127.1–1,089.0)US Virgin Islands: 349.8 (range of 42.4–516.3)US Virgin Islands: 343.9 (range of 39.4–514.6)
Spain: 393.1 (range of 212.2–612.9)Netherlands: 204.5 (range of 64.1–595.7)Spain: 144.5 (range of 91.2–254.7)
US Virgin Islands: 364.7 (range of 51.0–520.1)Spain: 150.9 (range of 94.1–267.1)Peru: 136.9 (range of 129.9–142.8)
Japan: 225.1 (range of 20.1–593.7)Belgium: 139.7 (range of 92.3–290.6)San Marino: 132.1 (range of 130.9–134.2)
Sweden: 223.1 (range of 83.1–894.3)Peru: 137.3 (range of 130.1–143.4)Kazakhstan: 121.4 (range of 53.4–183.5)
Romania: 216.1 (range of 106.9–384.4)San Marino: 137.2 (range of 132.4–151.2)Ecuador: 117.4 (range of 109.4–128.4)
Israel: 195.5 (range of 93.3–363.7)Sweden: 125.4 (range of 71.6–394.0)Belgium: 106.9 (range of 90.9–149.0)
Republic of Moldova: 192.3 (range of 105.4–312.8)United States of America: 125.1 (range of 106.0–157.1)Panama: 104.8 (range of 76.9–149.3)
United States of America: 189.0 (range of 141.3–266.7)Ecuador: 118.3 (range of 109.8–129.8)Mexico: 104.5 (range of 94.6–118.4)
Montenegro: 183.3 (range of 17.5–389.5)France: 111.4 (range of 67.5–243.7)Colombia: 94.7 (range of 81.5–112.1)

IHME’s projections are based on an epidemiological model that includes data on cases, deaths, and antibody prevalence, as well as location-specific COVID-19 testing rates, mobility, social distancing mandates, mask use, population density and age structure, and pneumonia seasonality, which shows a strong correlation with the trajectory of COVID-19.

The new projections, including additional forecasts of daily infections, are available at https://covid19.healthdata.org/ and will be regularly updated moving forward.

About the Institute for Health Metrics and Evaluation 

The Institute for Health Metrics and Evaluation (IHME) is an independent global health research organization at the University of Washington School of Medicine that provides rigorous and comparable measurement of the world’s most important health problems and evaluates the strategies used to address them. IHME is committed to transparency and makes this information widely available so that policymakers have the evidence they need to make informed decisions on allocating resources to improve population health. 

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